Interlocking structural unit



March 9, 1965 J. DOERING ETAL 3,172,508

INTERLUCKTNG STRUCTURAL UNIT Filed Jan. 19, 1962 3 Sheets-Sheet l naz Q March 9, 1965 J. DOERING ETAI.

INTERLOCKING STRUCTURAL UNIT 3 Sheets-Sheet 2 Filed Jan. 19, 1962 United States Patent O 3,172,508 INTERLCKING STRUCTURAL UNIT .lohn Deering, Meadowbrook, and Julian B. Finkel, Elkins Park, Pa., assignors to Fenestra Incorporated, Philadelphia, Ia., a corporation of Michigan Filed lIan. 19, 1962, Ser. No. 167,350 8 Claims. (Cl. 189--34) This invention relates to a structural unit adapted to be detachably interlocked with other substantially identical structural units to form a deck or surface suitable for use as a temporary take-off or landing field for tactical military aircraft, or as a military roadway, or as a missile launching pad, or for other temporary purposes, principally, but not necessarily, military.

It is an important object of the present invention to yprovide a detachable interlocking structural unit for the above purpose which is strong enough to take heavy loads but light enough in weight to be manually carried and handled for manual assembly with other units. In addition, the unit should preferably be floatable in water.

The requirement that the unit be iloatable in water permits units to be lashed together, thrown overboard, and pulled to shore during, for example, a marine landing.

The requirement that the structural unit be adapted to be detachably interlocked with other substantially identical structural units includes the specific requirement that the interlocking mechanism be capable of receiving the force of a landing aircraft without becoming disengaged while nevertheless allowing some degree of angular movement to a position below as well as above the horizontal plane of an adjoining unit interlocked therewith to accommodate some amount of unevenness in the supporting soil and to provide some give when the load of the landing aircraft is imposed.

The above objects are achieved by forming a structural unit out of a plurality of extruded tubular metal pieces, preferably aluminum, securing them together mechanically in side-by-side relationship, closing the open ends of the mechanically assembled tubular pieces with crossconnecting end pieces adapted to perform both a sealing and an interlocking function, and then welding all the pieces together to form an air-tight tubular structural unit. Each of the extruded pieces of which the unit is formed has a cross-sectional shape and size suitable for ready extrusion from conventional type extruding machines of reasonable size, thereby to assure their availability in large quantities on short notice in times of emergency. Each of the units thus formed is adapted to be detachably interlocked with other substantially identical units to form the temporary landing field for aircraft, the missile launching pad, or other service.

The structural unit of the present invention will become clear from a consideration of the following detailed description of a preferred form selected for illustration in the drawing in which:

FIG. 1 is a plan view, broken both longitudinally and transversely, showing two end connectors of a center structural unit in interlocking positions with the end connectors of adjoining structural units;

FIG. 2 is an elevational view, in section, along the line II--II of FIG. l;

FIG. 3 is an elevational View, in section, along the line Ill-III of FIGS. 1 and 2;

FIG. 4 is an elevational view, in section, along the line IV-IV of FIGS. 1 and 3;

FIG. 5 is a perspective rear view, broken medially, of one of the cross-end connectors;

FIG. 6 is a perspective front view, broken medially, of the cross-end connector shown in FIG. 5;

FIG. 7 is a perspective View, broken medially, of one of the two tubular edge pieces;

FIG. 8 is a perspective view, broken medially, of one of the tubular internal pieces, of which there are several side-by-side in the structural unit;

FIG. 9 is a perspective view, broken medially, of the other tubular edge piece;

FIG. 10 is a perspective front view, broken medially, of the other of the cross-end connectors;

FIG. 11 is a perspective rear view, broken medially, of the end connector shown in FIG. 10; and

FIG. 12 is a perspective view of one of the interlocking rods or pins.

In describing the preferred embodiment of the invention illustrated in the drawing, specific terminology has been resorted to for the sake of clarity. However, it is not the intention to be limited to the specillc terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

Referring lrst to FIGS. 7, 8 and 9, these figures show the three differently shaped pieces of extruded material, preferably aluminum, which are used to form one openended tubular structure. FIG, 7 shows the female edge piece 20, while FIG. 9 shows the male edge piece 40. Each structural unit contains one female and one male edge piece. FIG. 8 shows an interior piece 30 of which, ordinarily at least, a plurality are used in side-by-side relation between the two edge pieces 20 and 4t).

In a typical case, the female edge piece 20 may be of the order of 2 high and 4 wide. The male edge piece 40 may be of the order of 2 high and 3" wide. Each of the interior pieces 3i) may be of the order of 2 high and 5" wide. Each of the extruded pieces may be extruded to, or cut to, a 10 to 12-foot length. In a typical case, the unit may have about 7 interior pieces and an overall width of about 2 feet.

Each of the edge pieces 26 and 4t) is provided with one wedge-shaped channel 21 and 41, respectively. Each edge piece is also provided with one wedge-shaped flange 23 and 43, respectively. Each of the interior pieces 30 is provided with two wedge-shaped channels 31 and 32., and with two wedge-shaped flanges 33 and 34.

To assemble the unit, the edge pieces 20 and 4t), and the plurality of interior pieces 30, which are to be secured together in side-by-side relationship, are one-by-one placed end-to-end in such positions that the Wedge-shaped channel (or channels) are in alignment with the wedge-shaped flange (or flanges) to be received. One piece is then moved toward the other lengthwise to slide the flange (or flanges) into its channel (or channels) thereby to interlock mechanically the pieces together, as illustrated in FIG. 2. Later the mechanically interlocked pieces are welded together, as indicated in FIG. 2 by the welds I9.

The extruded pieces 20, 30, and 40 are of such shapes that when assembled they form an open-ended tubular structure having a continuous or plate deck 50 supported above a continuous or plate base 51 by a plurality of spaced-apart relatively thin webs or ribs 52 running lengthwise of the unit, each rib functioning as a supporting truss for the deck 50. The pieces 30 and 40 are provided with a ridged upper surface, the surface ridges 53V running longitudinally of the unit. The units are placed on the ground and interlocked with their major axes or long dimensions running transversely across the landing field. Thus, the surface ridges 53 run transversely across the eld and provide a degree of traction for the wheels of the aircraft.

The manner in which the structural unit is detachably interlocked along its two edges to adjacent units on either side is clearly seen in FIG. 2, and will now be described. Each female edge piece 20 is provided with an overwide channel 22 just below the deck level, and with a bottomless recess 24 just above the base level. The bottomless recess 24 is formed by offsetting the base member in an upward direction in the region below the channel 22, as shown in FIGS. 2 and 7. Each male edge piece 40 is provided at the deck level With a depending flange 44 and at the base level with a wide flat horizontally-disposed flange 4S. Adjacent units are connected together into interlocking relationship by a pivotal motion. For example, with a first structural unit lying flat on the ground, a second structural unit is placed alongside thereof in an inclined. position with the male edge of the second or inclined unit on or close to the ground parallel to the female edge of the first unit, and with the far edge (female edge) of the inclined unit raised above the ground. The interlock is then achieved by placing the depending flange 44 of the male edge into the overwide channel 22. of the first unit and lowering the second unit in an angular pivotal motion so that the horizontally-disposed wide flange 45 enters into the recess 24 of the first unit, thereby to form the interlock which is clearly depicted in FIG. 2. With the interlock arrangement shown, each interlocked unit may be moved pivotally to an angular position inclined slightly upward or downward relative to the plane of the adjoining interlocked unit, as may be required to accommodate uneven ground contour, or to allow limited movement in response to the force imposed by a landing aircraft, without breaking the interlock.

The open-end tubular unit formed by the assembly of one female and one male edge piece 20, 40 and a plurality of interior pieces 30, is, of course, not a complete unit. It is necessary to provide cross means at each end adapted for detachably interlocking the unit to the transverse end of an adjacent unit. In addition, since the complete unit is to be sufficiently buoyant to float on water, it is necessary that the open-ended tubular structure be sealed at each end.

Both of these requirements, i.e., the requirement of providing an end piece adapted to interlock with the end piece of an adjoining unit, and also the requirement of sealing the ends to form an air-tight tubular structure, are met by the provision of complementing female and male end-connectors 60 and 70. Two views of the female end-connector 60 are illustrated in FIGS. 5 and 6. Two views of the male end-connector 70 are illustrated in FIGS. 10 and 11.

The male end-connector 70 is provided with a flat rear wall surface '74 and an irregular front wall surface. The front wall includes a longitudinal centrally-disposed arcuate recess 73, an upper forwardly-disposed depending flange 7l, and a lower depending flange 72. Traction ridges are provided on its upper surface.

The female end-connector 60 is also provided with a flat rear wall surface 64 and an irregular front wall surface. The front wall includes a longitudinal centrallydisposed arcuate recess 63, an upper rearwardly-disposed longitudinal overwide groove or channel 61, and a lower forwardly-disposed longitudinal overwide groove or channel 62.

As seen in FIG. 3, a female end-connector `60 (of the type shown in FIGS. and 6) is secured, as by welding, across one end of one open-ended tubular unit for interlocking with a male end-connector 70 of another unit. The male end-connector is of the type shown in FIGS. 10 and l1 and is secured, as by welding, across the end of an adjoining unit. Similarly, a male end-connector '70 is welded across the other end of the one unit for interlocking with a female end-connector 60 of another adjoining unit. Interlocking is achieved by raising the male end-connector of one of the units above the female end-connector of the other unit, moving the units together and allowing the upper forward and lower depending flanges '71 and 72, respectively, of the male connector 70 to drop respectively into the overwide rearward and forward channels 6l and 62 of the female connector 60 of the other unit. To complete the interlocking, a cylindrical rod or pin 80, such as is illustrated in FIG. 12, is inserted into the hole formed by the arcuate recesses 63 and '73 of the female and male end-connectors, respec tively. The diameter of pin is slightly smaller than the diameter of the circular hole created by the recesses '73 when the interlocked connectors Sil and 7d are in the relative positions shown in FIG. 3. In these relative positions, the depending flanges '71, 72 of the male end-connector are approximately centered in the overwide slots 6l., 62 of the female end-connector, as illustrated in FIG. 3. Each of the interlocked end connectors eti, 'itl is then free to move pivotally relative to the other, thereby to accommodate the interlocked units to contour of the ground on which the units are placed, and thereby' to allow one unit to give relative to the other under the force of a landing aircraft. To facilitate the pivotal movement, the outer edge of the forward depending flange '71 of the male end-connector may preferably be rounded or chamfered, as may also the outer edge of the upstanding flange which forms the lower channel 62 of the female end-connector.

While the structural arrangement of the end connectors 6G, 7l)` and pin 80 allows pivotal movement of one structural unit relative to the other, the two interlocked units are nevertheless locked against separation even when the heavy load of a landing aircraft is suddenly imposed thereon.

When welded into place across the ends of the openended tubular structure (formed by one each of edge pieces Ztl and tu and one or more of interior pieces 3G), end-connectors et) and Til effect a sealing or air-tight closing of the open tubular passages, thereby forming an airtight tubular structure unit having sufficient buoyancy to float on water. The male end-connector '70 (FGS. l0 and ll) is placed across the open-ended structure (formed by the pieces 2li, 3l), 4t!) With the flat side 74:- of the male end-connector facing the open-ended structure. The male connector 7@ is so positioned that the rear wall 74 of step-down portion 7S abuts against and closes that portion of the right end of the female edge piece Ztl lying between channel 22 and recess Z4. The female end connector 6* (FIGS. 5 and 6) is placed across the other end of the open-ended structure with the flat side 64 of the female end-connector facing the openended structure. The female end-connector 60 is so positioned that the rear wall 64 of step-down portion 65 abuts against and closes that portion of the left end of the female edge piece 20 lying between channel 22 and recess 24. The absence of material in the cut-away areas above the stepdown portions 65, 75 of the end connectors facilitates edge-wise assembly and inter-locking of the structural units.

Landing fields having an impact area of 1500 feet by feet and comprising an assembly of structural units Vof the type described and illustrated herein are able to receive an impact of 100,000 pounds per wheel of landing craft. The field is readily laid, is strong and tight, may be put together and disassembled quickly and frequently, is dust free, and has good flexibility to accommodate uneven soil conditions and the impact of landing aircraft. The individual structural units are air-tight, buoyant and floatable, are'mechanically interlocked as well as welded, and are formed of individual extruded pieces which may be produced on extrusion machines of common size and type. The end-connectors, when interlocked, function as a bi-directional moment transfer device, adapted to transfer moment in either of two directions.

Without intending to be limited to particular dimensions or to particular material, it may be said that a unit according to the present invention may be comprised of extruded pieces of aluminum having a deck /lG thick, a base 5,32 thick and truss ribs 3/16 thick. The total weight of a unit is about l5() pounds. While aluminum is the preferred material at present, other suitable materials may be employed. The arcuate recesses '73, 63

in the male and female endconnectors 70, 60 respectively, form, when the depending flanges 71, 72 are approximately centered in the overwide channels 61, 62, a cylindrical hole having a diameter of one-half inch. Locking pin 80 has a diameter of 7/16. Channels 61 and 62 are 5/16 wide while depending flanges 71, 72 are EAG thick.

While the preferred embodiments of this invention have been described in some detail, it will be obvious to one skilled inthe art that various modifications may be made without departing from the invention as hereinafter` claimed.

Having thus described our invention, we claim as follows:

1. A structural metal unit for detachably interlocking with other substantially identical structural units to form a deck or door of variable area, each of said units cornprising: an elongated rectangular structure having a spaced apart upper deck surface and a lower base surface; male and female connectors secured across opposite ends of the said structure, each of said end connectors having an irregular front wall surface which includes a horizontally disposed recess open at one side and located about midway between the upper and lower surfaces of the end connectors, the front wall of said male end connector having a first depending flange located above and forward of its said recess and a second depending flange located below and rearward of said first flange, the front wall of said female connector having a first overwide groove open upwardly and located above and somewhat rearward of its said recess for receiving said first flange of a male end connector of an adjoining unit and having a second overwide groove open upwardly and located below and forward of its recess for receiving said second flange of said male end connector of the adjoining unit, the open-sided recesses of said male and female end connectors when adjoining units are interlocked forming a substantially closed slot for receiving a locking bar.

2. A structural unit as claimed in claim l further characterized in that said structure is comprised of a plurality of elongated extruded metal sections mechanically secured together along their lengthwise edges at the deck and base levels, said sections including elongated male and female edge sections.

3. A structural unit as claimed in claim 2 further characterized in that said male edge section has a flange depending from its longitudinal edge at the deck level and has a wide horizontally-disposed longitudinally-extending flange at the base level beneath said depending deck flange, and further characterized in that said female edge section edge has an overwide groove at the deck level for receiving the depending deck ange of an adjoining interlocking male edge section, said groove being substantially wider than said deck ange, said female edge section also having, at substantially the base level beneath said overwide deck groove, a flat horizontally-disposed portion offset above the remainder of the base and forming therebeneath a recess for receiving the wide horizontally-disposed base flange of an adjoining interlocking male edge section.

4. A structural unit as claimed in claim 3 further characterized in that said front walls of said male and female end connectors are complementary, the open side of the recess of the male end connector of one unit facing the open side of the recess of the female end connector of another unit when the two units are in interlocking relation and yforming a slot for receiving a locking bar of a size corresponding to the said slot.

5. A structural unit as claimed in claim 4 further char- CII acterized in that the cross-section configuration of the front wall of the male end connector is identical to that of the female end connector when the latter is viewed in inverted reversed position.

6. A structural unit as claimed in claim 1 further characterized in that said structural unit includes male and female edge connectors at opposite longitudinal edges, said male edge connector having a flange depending from the deck level and a wide horizontally-disposed ange at the base level beneath said depending deck flange, said female edge connector having an overwide groove at the deck level for receiving the depending deck flange of an adjoining interlocking unit, said groove being substantially wider than said deck flange, said female edge connector also having, at substantially the base level beneath said overwide deck channel, a flat horizontally-disposed portion offset above the remainder of the base and forming therebeneath a recess for receiving the wide horizontally-disposed base flange of an adjoining interlocking unit.

7. A temporary deck or supporting floor comprising a plurality of structural units detachably interlocked with other substantially identical structural units, each of said structural units including an elongated horizontallydisposed rectangular plate deck member supported by lengthwise extending ribs above a horizontally-disposed rectangular plate base member forming a tubular structure, male and female cross end connectors secured across opposite ends of the said tubular structure, each of said end connectors having irregular front wall surfaces which include a horizontally-disposed recess open at one side and located about midway between the upper and lower surfaces of the end connectors, the front wall of said male end connector having a first depending frange located above and forward of its recess and a second depending flange located below and substantially in line with said recess, the front wall of said female end connector having a first overwide groove open upwardly and located above and rearward of its recess receiving said first depending fiange of the male end connector of an adjoining unit, and having a second overwide groove open upwardly and located below its recess receiving said second depending ange of the male end connector of said adjoining unit, said recesses of the interlocked male and female end connectors forming a substantially closed slot, and a locking bar in said slot having dimensions corresponding to those of said slot.

8. A structure as claimed in claim 7 characterized in that said recesses are arcuate forming a slot of generally circular cross-section, and in that said locking bar is cylindrical.

References Cited by the Examiner UNITED STATES PATENTS 2,956,653 10/60 Liskey 189--34 3,023,834 3/62 Buchanan 189-34 3,039,575 6/62 Graham 189-83 3,062,338 11/62 De Ridder et al. 189-34 FOREIGN PATENTS 835,260 5/60 Canada. 615,818 3/61 Canada. 615,819 3/61 Canada. 615,820 3/61 Canada.

16,305 10/55 Germany.

JACOB L. NACKENOFF, Primary Examiner. 

1. A STRUCTURAL METAL UNIT FOR DETACHABLY INTERLOCKING WITH OTHER SUBSTANTIALLY IDENTICAL STRUCTURAL UNITS TO FORM A DECK OR FLOOR OF VARIABLE AREA, EACH OF SAID UNITS COMPRISING: AN ELONGATED RECTANGULAR STRUCTURE HAVING A SPACED APART UPPER DECK SURFACE AND A LOWER BASE SURFACE; MALE AND FEMALE CONNECTORS SECURED ACROSS OPPOSITE ENDS OF THE SAID STRUCTURE, EACH OF SAID END CONNECTORS HAVING AN IRREGULAR FRONT WALL SURFACE WHICH INCLUDES A HORIZONTALLY DISPOSED RECESS OPEN AT ONE SIDE AND LOCATED ABOUT MIDWAY BETWEEN THE UPPER AND LOWER SURFACES OF THE END CONNECTORS, THE FRONT WALL OF SAID MALE END CONNECTOR HAVING A FIRST DEPENDING FLANGE LOCATED ABOVE AND FORWARD OF ITS SAID RECESS AND A SECOND DEPENDING FLANGE LOCATED BELOW AND REARWARD OF SAID FIRST FLANGE, THE FRONT WALL OF SAID FEMALE CONNECTOR HAVING A FIRST OVERWIDE GROOVE OPEN UPWARDLY AND LOCATED ABOVE AND SOMEWHAT REARWARD OF ITS SAID RECESS FOR RECEIVING SAID FIRST FLANGE OF A MALE END CONNECTOR OF AN ADJOINING UNIT AND HAVING A SECOND OVERWIDE GROOVE OPEN UPWARDLY AND LOCATED BELOW AND FORWARD OF ITS RECESS FOR RECEIVING SAID SECOND FLANGE OF SAID MALE END CONNECTOR OF THE ADJOINING UNIT, THE OPEN-SIDED RECESSES OF SAID MALE AND FEMALE END CONNECTORS WHEN ADJOINING UNITS ARE INTERLOCKED FORMING A SUBSTANTIALLY CLOSED SLOT FOR RECEIVING A LOCKING BAR. 